Simple gocql batch example

main.go

package main

import (
	"github.com/tux21b/gocql"
	"log"
)

// create table foo (
// bar bigint,
// baz ascii,
// primary key (bar)
// );

func main() {
	cluster := gocql.NewCluster("127.0.0.1")
	cluster.Keyspace = "logs_ks"
	session, err := cluster.CreateSession()

	if err != nil {
		log.Panic(err)
	}

	batch := gocql.NewBatch(gocql.LoggedBatch)
	stmt := "INSERT INTO foo (bar,baz) VALUES (?,?)"

	for i := 0; i < 10000; i++ {
		batch.Query(stmt, i, "foo")

		if i%50 == 0 {
			err = session.ExecuteBatch(batch)
			if err != nil {
				log.Panic(err)
			}
			batch = gocql.NewBatch(gocql.LoggedBatch)
		}
	}

	err = session.ExecuteBatch(batch)
	if err != nil {
		log.Panic(err)
	}
}

Be careful, you're batching queries with different partition keys, which is an anti-pattern that can lead to poor performance: https://docs.datastax.com/en/cql/3.3/cql/cql_using/useBatchBadExample.html

In the line 23 and 34
gocql.NewBatch(gocql.LoggedBatch)
Use session.NewBatch instead